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Providing evidence to improve practice

Individual study: Chemical control of New Zealand pygmyweed Crassula helmsii at Langham’s Ponds, Surrey, England

Published source details

(2004) Chemical control of Australian swamp stonecrop (New Zealand Pygmy Weed) Crassula helmsii. The National Trust Conservation Newsletter, 8, 2-3


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Crassula helmsii: Use a combination of control measures Control of Freshwater Invasive Species

A before-and-after study in 2002-2003 at a single pond in Surrey, UK (Anonymous 2004) reported that covering C. helmsii with carpet strips followed by the application of glyphosate reduced the area of the plant, although no statistical tests were carried out. One year after glyphosate application approximately 80% of C. helmsii had been killed. In autumn 2002, strips of carpet were placed over C. helmsii and weighted down wherever possible on the pond edge and in shallow water. In July-August 2003 the carpet was removed and the glyphosate-based herbicide Roundup was applied twice.

 

Crassula helmsii: Use lightproof barriers to control plants Control of Freshwater Invasive Species

A before-and-after study in 2002-2004 at a single pond in Surrey, UK (Anonymous 2004) reported that covering C. helmsii with carpet strips followed by the application of glyphosate reduced the area of the plant, although no statistical tests were carried out. One year after glyphosate treatment approximately 80% of C. helmsii had been killed, although it is not clear whether this was a direct result of the use of carpet or was due to herbicide application. In autumn 2002, strips of carpet were placed over C. helmsii and weighted down wherever possible on the pond edge and in shallow water. In July-August 2003 the carpet was removed and the glyphosate-based herbicide Roundup was applied twice.

 

Crassula helmsii: Chemical control using herbicides Control of Freshwater Invasive Species

A before-and-after study in 2002-2003 at a single pond in Surrey, UK (Anonymous 2004) reported that covering plants with carpet strips and then applying glyphosate reduced the area of C. helmsii, although no statistical tests were carried out. Approximately 80% of C. helmsii was killed, although it is not clear whether this was a result of herbicide application or was due to the use of carpet to prevent light reaching the plant. In autumn 2002, strips of carpet were placed over C. helmsii wherever possible on the pond edge and in shallow water. In July-August 2003 the carpet was removed and the glyphosate-based herbicide Roundup was applied twice (concentration not given). C. helmsii cover was assessed in June 2004.